Node.js up to 24.22.2/26.13.0 Alt-Svc src/node_http2.cc Http2Session.altsvc heap-based overflow

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.5$0-$5k0.31+

Summaryinfo

A vulnerability described as problematic has been identified in Node.js up to 24.22.2/26.13.0. This affects the function Http2Session.altsvc of the file src/node_http2.cc of the component Alt-Svc Handler. Executing a manipulation can lead to heap-based overflow. This vulnerability is handled as CVE-2026-123828. The attack can be executed remotely. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as problematic was found in Node.js up to 24.22.2/26.13.0. This vulnerability affects the function Http2Session.altsvc of the file src/node_http2.cc of the component Alt-Svc Handler. The manipulation with an unknown input leads to a heap-based overflow vulnerability. The CWE definition for the vulnerability is CWE-122. The product writes past the end of a buffer that was allocated on the heap. As an impact it is known to affect availability. CVE summarizes:

A one-byte heap buffer overflow in Node.js HTTP/2 Alt-Svc handling lets a remote, unauthenticated attacker corrupt process memory. When an application passes an attacker-controlled value such as a request's :authority header to Http2Session.altsvc(), the AltSvc implementation in src/node_http2.cc allocates a buffer sized to the origin length and then writes it with a null terminator, placing one byte past the end of the allocation. A single request carrying a long but syntactically valid :authority triggers the out-of-bounds write, which aborts the process and serves as a remote heap-corruption primitive. This vulnerability affects Node.js 26.x and 24.x.

The advisory is shared for download at nodejs.org. This vulnerability was named CVE-2026-123828 since 11/06/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available.

Upgrading to version 24.22.3 or 26.13.1 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.6
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.9
CNA Vector (openjs): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Heap-based overflow
CWE: CWE-122 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Node.js 24.22.3/26.13.1

Timelineinfo

11/06/2026 CVE reserved
11/11/2026 +5 days Advisory disclosed
11/11/2026 +0 days VulDB entry created
11/11/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: nodejs.org
Status: Confirmed

CNA: openjs
CVE: CVE-2026-123828 (🔒)

GCVE (CVE): GCVE-0-2026-123828
GCVE (VulDB): GCVE-100-435916

Entryinfo

Created: 11/11/2026 19:34
Changes: 11/11/2026 19:34 (65)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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